15868644489 has 12 divisors (see below), whose sum is σ = 23048015172. Its totient is φ = 10520647200.

The previous prime is 15868644487. The next prime is 15868644563. The reversal of 15868644489 is 98444686851.

15868644489 is a `hidden beast` number, since 1 + 58 + 68 + 6 + 44 + 489 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 857494089 + 15011150400 = 29283^2 + 122520^2 .

It is not a de Polignac number, because 15868644489 - 2¹ = 15868644487 is a prime.

It is a super-2 number, since 2×15868644489² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15868644487) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4869042 + ... + 4872299.

It is an arithmetic number, because the mean of its divisors is an integer number (1920667931).

Almost surely, 2^15868644489 is an apocalyptic number.

It is an amenable number.

15868644489 is a deficient number, since it is larger than the sum of its proper divisors (7179370683).

15868644489 is a wasteful number, since it uses less digits than its factorization.

15868644489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9741528 (or 9741525 counting only the distinct ones).

The product of its digits is 53084160, while the sum is 63.

The spelling of 15868644489 in words is "fifteen billion, eight hundred sixty-eight million, six hundred forty-four thousand, four hundred eighty-nine".